Improvements in or relating to devices for sampling, drainage or infusion of liquids from or to the human or animal body

Description

[0001] This invention relates to the sampling, drainage or infusion of liquids from or to the human or animal body and in particular but not exclusively to a device for use in intravenous sampling or infusion via a cannula and to an adaptor for use in connecting the device to a catheter.

[0002] It is known for a cannula to be used in sampling or infusion of liquids in a device in which the cannula communicates with a chamber having one or more ports through which a needle or catheter may pass into the cannula. In such devices liquid may be sampled or infused by connection to a drain or a source of liquid respectively by means of a catheter. It has hitherto been a problem with such devices that an airlock may develop in the chamber or in the catheter. A further problem is that liquid may be lost during coupling of the device to catheters and the like and that under certain circumstances the loss of liquid may be hazardous for example when sampling blood from the body of an infective patient or when supplying potentially irritant medication with associated hazards to the patient and operator.

[0003] It is known from GB 2048681 and DE-3100442 to provide apparatus for use in the sampling or infusion of liquids from or to the human or animal body comprising a device defining a chamber for receiving fluid, a cannula in communication with the chamber, valve means comprising an elastomeric membrane having a central puncture operable in an open condition to connect the chamber with a source for drain of liquid and in a closed condition to seal the chamber therefrom, a ducted member having a distal end for use in penetrating the member at the puncture site to provide a flow path through the membrane in an open condition of the valve means, the membrane being self-sealing on withdrawal of the member in a closed condition of the valve means, and the device having connection means for connecting to a catheter in communication with the source or drain of liquid.

[0004] A disadvantage of such apparatus is that when the catheter is disconnected from the device a volume of liquid remaining in the ducted member is liable to be spilt. A further disadvantage is that air can be trapped in the device during introduction of the cannula into a patient and during connection of the catheter to the device.

[0005] According to the present invention, such disadvantages are overcome by an apparatus as defined in Claim 1 which is characterised by the connection means comprising a proximal end portion of the ducted member and by the device further comprising chamber venting means allowing the escape of air from the chamber whilst preventing the escape of liquid therefrom.

[0006] Preferably, the venting means is a hydrophobic filter comprising an air permeable barrier of a hydrophobic material. Preferably, this material is polytetrafluoroethylene having a pore size in the range 0.2 to 0.5 microns.

[0007] Advantageously, the valve means may be disposed in a position and orientation permitting an elongate member such as an introducing needle or a probe catheter penetrating the valve means to extend linerarly through the chamber and the cannula. An advantage of such an arrangement is that an introducing needle may be inserted through the chamber and the cannula into the body so that the cannula may then be introduced into the body or alternatively a probe catheter may be passed through the chamber and through the already introduced cannula so as to extend into the body.

[0008] Advantageously, the cannula communicates with one end of the chamber, the valve means is disposed at the other end of the chamber for admitting an elongate member and a second valve means is disposed at an intermediate position in a side port of the chamber. An advantage of such an arrangement is that a second means of injecting or sampling liquid is provided through the second valve means.

[0009] Preferably, the cannula communicates with one end of the chamber whilst the venting means is disposed at or adjacent to the other end of the chamber so that in use the venting means is disposed as far away as possible from the body and releases air from the uppermost portion of the chamber. An advantage of such an arrangement is that the venting means is then optimally located for eliminating air locks.

[0010] The term puncture is used above to indicate that the membrane has been pierced for example by a needle so that in the absence of any deforming forces the elastomeric qualities of the membrane effect a self sealing action.

[0011] Preferably, such a membrane has an outer surface with respect to the chamber lying substantially flush with the surrounding outer surface of the device. Such an arrangement avoids the accumulation of matter which might serve as a bacteria trap.

[0012] Preferably, the device includes means for fastening the co-operating member to the device in the open condition of the valve means so that the co-operating member constitutes an adaptor which is supported and secured to the device. Conveniently the fastening means is a threaded fastener which has the added advantage of providing a controlled penetrating force to the member during connection.

[0013] Preferably, the membrane is of an uncured rubber material such as gumstock.

[0014] Alternatively, the membrane may be of silicone rubber.

[0015] The term catheter as used above is intended to include the tubing of a giving set or drainage set, or a syringe which may for example have a luer connector, or any other type of tube used in the sampling, drainage or infusion of liquids.

[0016] Such an adaptor is particularly advantageous where a flush fitting membrane is used in the device and where conventional catheter connectors are to be employed so that conveniently the adaptor may include a luer connector.

[0017] Advantageously the ducted member in such an adaptor is sealable at its distal end to prevent loss of liquid whilst not connected to the device and includes duct venting means allowing the escape of air from the ducted member whilst preventing the escape of liquid therefrom. This is useful when for example the adaptor is connected to an infusion prior to being connected to the device.

[0018] Preferably the adaptor includes a detachable cap having a hydrophobic filter. Conveniently the cap is threadably engageable with the adaptor.

[0019] Particular embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings of which:

Figure 1 is a part sectioned elevation of a device according to the present invention having a membrane valve and showing an adaptor and a luer connector prior to assembly;

Figure 2 is a plan view of the device of Figure 1;

Figure 3 is a sectional view of the adaptor of Figure 1 having a cap in a sealing position;

Figure 4 is a similar view of the adaptor of Figure 3 and showing a cap prior to sealing;

Figure 5 shows the adaptor of Figure 3 connected with the device of Figure 1; and

Figure 6 shows an alternative device having two valve means of the silicone rubber type.

[0020] The device of Figure 1 has a chamber (1) and a cannula (2). A valve means comprising a membrane (3) is disposed opposite to and in line with the cannula (2) and has a central puncture (4). The membrane material is an uncured natural rubber and in this example is W-1028 gum having a thickness of 1/16 inch (0.159cm).

[0021] Venting means comprising a chamber filter (5) obturates a side port (6) of the chamber and comprises a polytetrafluoroethylene barrier having a pore size of 0.2 microns.

[0022] Wings (7) extend on either side of the chamber for ease of attachment of the device to a body (not shown) for example by means of adhesive tape.

[0023] An adaptor (8) includes a ducted member (9) which is tapered to facilitate penetration through the membrane (3) at the puncture site (4). The adaptor is fitted to the device by a threaded fastener comprising female threads (10) on the adaptor which engage male lugs (11) on the device so that during threaded engagement the ducted member is progressively urged through the membrane.

[0024] A catheter (12) having a female luer connector 13 may be connected to the adaptor (8) by engaging the male luer connector (14).

[0025] The adaptor (8) is provided with a detachable cap (15) as shown in Figures 3 and 4 so that in the sealing arrangement shown in Figure 3 the cap is sealed to the adaptor by a threaded connector 16. The cap (15) includes a hydrophobic cap filter (17) comprising a barrier of polytetrafluoroethylene of pore size 0.2 microns.

[0026] In Figure 5 the adaptor (8) without the cap (15) is shown connected to the device such that the ducted member (9) extends through the membrane (3) thereby creating a flow path communicating with the chamber.

[0027] Figure 6 shows an alternative device having an additional side port (18) accommodating a silicone rubber valve (19). In this embodiment the valve means (20) opposing the cannula is also of silicone rubber.

[0028] The device and the adaptor (8) as shown in Figures 1 to 5 may for example by used in connecting an intravenous infusion to a human patient by inserting the cannula into the patient and connecting the adaptor to a catheter comprising the tubing of a giving set. The cannula may be of the steel needle type in which case cannulation can by direct injection or the cannula may be of a plastics material in which case cannulation requires the use of an introducing needle which is initially inserted through the membrane (3) at the puncture site (4) so as to extend through the cannula (2) and may then be withdrawn after cannulation.

[0029] The chamber (1) serves as a flashback chamber during cannulation so that preferably the chamber is of a transparent plastics material so that the chamber may be observed to be filling with blood. During flashback air is expelled through the chamber filter (5) which prevents loss of blood by virtue of its hydrophobic properties. The pore size of the filter (5) is selected to be of the order of 0.2 microns which prevents the ingress of bacteria and the material of the filter is chosen to be non-toxic and non-reactive with the chamber contents, for example polytetrafluoroethylene.

[0030] For the purpose of volume fluid infusion, before connecting the adaptor (8) to the device it is first necessary to prime the tubing (12) of the giving set and the adaptor with the infusion liquid and this may be carried out by connecting the adaptor to the tubing using the male and female luer connectors (14 and 13) and with the cap (15) fitted to the adaptor. Liquid from the giving set is then admitted to the tubing and fills both the tubing and adaptor completely with air being expelled through the filter (17). The use of a hydrophobic filter (17) in the cap (15) ensures that no liquid is lost during the priming operation and the use of a filter of polytetrafluoroethylene with pore size 0.2 microns ensures that the liquid is not contaminated by bacteria.

[0031] To connect the primed adaptor and tubing to the device the tubing (12) which is of a soft plastics material is clamped adjacent to the adaptor (8) and the cap (15) is then removed. No loss of liquid will occur at this stage provided the tubing (12) is adequately clamped to prevent any flow of liquid. The cap may then be discarded and is preferably is regarded as being a disposable item.

[0032] The adaptor (8) is then fitted to the device by urging the ducted member (9) through the puncture (4) of the membrane (3) and screwing the adaptor in place by means of the threaded fastener (10 and 11). The tubing may then be unclamped to release the flow of liquid and in this condition as shown in Figure 5 the flow path is established from the tubing through the adaptor and into the chamber for delivery to the patient via the cannula. The giving set may be disconnected from the patient by clamping the tubing and unscrewing the adaptor from the device to withdraw the ducted member (9) so that the membrane (3) relaxes to its closed position as shown in Figure 1.

[0033] The setting up of a giving set for an intravenous infusion may therefore be a controlled and closed procedure using the device and adaptor of the present invention. Furthermore it is envisaged that each new giving set may be supplied with a disposable adaptor including a cap.

[0034] Additional medication may be injected to the chamber (1) where an additional port (18) is provided as shown in Figure 6.

[0035] The device and adaptor in accordance with the present invention is particularly advantageous where a patient requires self treatment involving infusion as in the case of patients suffering from haemophilia and other blood disorders. The self sealing nature of the membrane valve (3) allows the attachment of a syringe to a cannula to be a simple one hand operation. The device also has application in chemotherapy, dialysis and anaesthesia. The inclusion of the hydrophobic filter reduces the risk of air embolism or infection and enables flashback to be safely controlled without blood spillage. The device may also be used in the taking of blood samples and is particularly advantageous in obtaining samples from patients suspected of having infectious diseases where it is essential to minimise the risk of blood spillage.

[0036] Whilst membrane type valves have been shown in the preferred embodiments other types of valve may be used in the device, such as flap valves or ball valves and may be actuated either by a co-operating member or by fluid pressure.

[0037] A device in accordance with the present invention may be used not only for intravenous infusion and sampling but in cannulating any body cavity for infusion or drainage and may include specialised adaptations of the cannula portion of the device for such use.

[0038] It is also envisaged that a filter as disclosed above may be used in a cap attachable to the tubing of a giving set to generally avoid spillage during priming. This would avoid the present disadvantage whereby a quantity of liquid is generally lost when preparing to connect the giving set to any apparatus in order to remove air from the system. such a filter could be supplied in a disposable cap which would allow air to be vented during priming, the tubing of the giving set then being clamped and the cap discarded.

Claims

1. Apparatus for use in the sampling or infusion of liquids from or to the human or animal body comprising a device defining a chamber (1) for receiving fluid, a cannula (2) in communication with the chamber (1), valve means (3) comprising an elastomeric membrane having a central puncture (4) operable in an open condition to connect the chamber (1) with a source or drain of liquid and in a closed condition to seal the chamber (1) therefrom, a ducted member (9) having a distal end for use in penetrating the membrane at the puncture site (4) to provide a flow path through the membrane in an open condition of the valve means (3), the membrane being self-sealing on withdrawal of the member (9) in a closed condition of the valve means (3), characterised in that the device comprises coupling means provided at the proximal end portion of the ducted member for connection to a catheter in communication with the source or drain of liquid; and in that the device further comprises chamber venting means (5) allowing the escape of air from the chamber (1) whilst preventing the escape of liquid therefrom.

2. Apparatus as claimed in Claim 1 wherein the venting means (5) is a hydrophobic filter comprising an air permeable barrier of a hydrophobic material, preferably polytetrafluoroethylene having a pore size in the range of 0.2 to 0.5 micron.

3. Apparatus as claimed in Claim 1 or Claim 2 wherein the valve means (3) is disposed in a position and orientation permitting an elongate member penetrating the valve means (3) to extend linearly through the chamber (1) and the cannula (2).

4. Apparatus as claimed in Claim 3 wherein the cannula (2) communicates with one end of the chamber (1), the valve means (3) is disposed at the opposite end of the chamber for admitting an elongate member and a second valve means (19) is disposed at an intermediate position in a side port (18) of the chamber.

5. Apparatus as claimed in Claim 3 or Claim 4 wherein the cannula (2) communicates with one end of the chamber (1) and the venting means (5) is disposed at or adjacent to the opposite end of the chamber so that, in use, the venting means (5) is disposed as far away as possible from the body and so that, in use, the venting means releases air from the uppermost portion of the chamber.

6. Apparatus as claimed in any preceding claim in which the outer surface of the membrane with respect to the chamber lies substantially flush with the surrounding outer surface of the device.

7. Apparatus as claimed in any preceding claim wherein the ducted member constitutes an adaptor (8) which includes means (10) for fastening the ducted member to the device in the open condition of the valve means.

8. Apparatus as claimed in any preceding claim wherein the membrane is made from an uncured rubber material or from silicone rubber.

Revendications

1. Appareil utilisable dans l'échantillonnage ou la perfusion de liquides depuis ou dans le corps humain ou le corps d'un animal, comprenant un dispositif formant une chambre (1) destiné à recevoir un liquide, une canule (2) qui est en communication avec la chambre (1), un dispositif formant soupape (3) comprenant une membrane élastomère présentant une perforation centrale (4) utilisable, a l'état ouvert, pour relier la chambre (1) à une source ou un drain de liquide et, à l'état fermé, pour séparer de façon étanche la chambre (1) par rapport à cette source ou ce drain, un élément en forme de conduit (9) comportant une extrémité distale utilisable pour la pénétration à travers la membrane à l'endroit de perforation (4) pour assurer un parcours de circulation à travers la membrane dans l'état ouvert du dispositif formant soupape (3), la membrane étant à auto-scellement lors du retrait de l'élément (9) dans l'état fermé du dispositif formant soupape (3), caractérisé en ce que le dispositif comprend des moyens d'accouplement prévus à la partie extrême. proximale de l'élément en forme de conduit en vue d'une connexion à un cathéter qui est en communication avec la source ou drain de liquide, et en ce que ce dispositif comprend en outre des moyens (5) de ventilation de la chambre, permettant l'échappement de l'air depuis cette chambre (1), tout en empêchant l'échappement de liquide depuis cette chambre.

2. Appareil suivant la revendication 1, caractérisé en ce que les moyens de ventilation (5) consistent en un filtre hydrophobe comprenant une barrière perméable à l'air, faite d'une matière hydrophobe, de préférence en polytétrafluoréthylène, d'une taille des pores de l'ordre de 0,02 à 0,05 micron.

3. Appareil suivant la revendication 1 ou la revendication 2, caractérisé en ce que le dispositif formant soupape (3) est placé dans une position et suivant une orientation permettant à un élément allongé pénétrant dans ce dispositif formant soupape (3) de s'étendre linéairement à travers la chambre (1) et la canule (2).

4. Appareil suivant la revendication 3, caractérisé en ce que la canule (2) communique avec une extrémité de la chambre (1), le dispositif formant soupape (3) est disposé à l'extrémité opposée de la chambre pour l'admission d'un élément allongé, et un second dispositif formant soupape (19) est prévu en une position intermédiaire das un passage latéral (18) de la chambre.

5. Appareil suivant la revendication 3 ou la revendication 4, caractérisé en ce que la canule (2) communique avec une extrémité de la chambre (1), et les moyens de ventilation (5) sont disposés à l'extrémité opposée ou au voisinage de l'extrémité opposée de la chambre de manière que, lors de l'utilisation, les moyens de ventilation (5) soient disposés aussi loin que possible du corps, et de sorte que, lors de l'utilisation, ces moyens de ventilation libèrent l'air depuis la partie supérieure de la chambre.

6. Appareil suivant l'une quelconque des revendications précédentes, caractérisé en ce que la surface extérieure de la membrane par rapport à la chambre se situe sensiblement de niveau avec la surface extérieure environnante du dispositif.

7. Appareil suivant l'une quelconque des revendications précédentes, caractérisé en ce que l'élément en forme de conduit constitue un adaptateur (8) qui comporte des moyens (10) pour attacher l'élément en forme de conduit au dispositif dans l'état ouvert du dispositif formant soupape.

8. Appareil suivant l'une quelconque des revendications précédentes, caractérisé en ce que la membrane est faire d'une matière caoutchouteuse non vulcanisée ou d'un caoutchouc siliconé.

Ansprüche

1. Vorrichtung zur Verwendung bei der Entnahme oder Infusion von Flüssigkeiten aus dem oder in den menschlichen oder tierischen Körper, umfassend eine Einrichtung, die definiert ist durch eine Kammer (1) zur Aufnahme von Fluid, eine Kanüle (2) in Kommunikation mit der Kammer (1), ein ventilmittel (3), das eine elastomere Membran mit einer zentralen Punktion (4) umfaßt und bedienbar ist, um in einem offenen Zustand die Kammer (1) mit einer Quelle oder einem Ablauf von Flüssigkeit zu verbinden und in einem geschlossenen Zustand die Kammer (1) davon abzudichten, ein Leitungsteil (9) mit einem distalen Ende zur Verwendung beim Durchdringen der Membran an der Punktionsstelle (4), um einen Fließweg durch die Membran in einem offenen Zustand des Ventilmittels (3) vorzusehen, wobei die Membran selbstabdichtend bei Rückzug des Teils (9) in einem geschlossenen Zustand des Ventilmittels (3) ist, dadurch gekennzeichnet, daß die Einrichtung ein Kupplungsmittel enthält, das am proximalen Endteil des Leitungsteils für Verbindung zu einem Katheter in Kommunikation mit der Quelle oder dem Ablauf von Flüssigkeit vorgesehen ist, und daß die Einrichtung zusätzlich ein Kammerentlüftungsmittel (5) enthält, das den Austritt von Luft aus der Kammer (1) erlaubt, während es den Austritt von Flüssigkeit daraus verhindert.

2. Vorrichtung nach Anspruch 1, worin das Entlüftungsmittel (5) ein hydrophober Filter ist, der eine luftdurchlässige Barriere eines hydrophoben Materials, vorzugsweise Polytetrafluorethylen, mit einer Porengröße im Bereich von 0,2 bis 0,5 Mikron enthält.

3. Vorrichtung nach Anspruch 1 oder 2, worin das Ventilmittel (3) in einer Lage und Orientierung angeordnet ist, die einem langgestreckten Teil das Durchdringen des Ventilmittels (3) erlaubt, um sich linear durch die Kammer (1) und die Kanüle (2) zu erstrecken.

4. Vorrichtung nach Anspruch 3, worin die Kanüle (2) mit einem Ende der Kammer (1) kommuniziert, das Ventilmittel (3) am entgegengesetzten Ende der Kammer für den Zutritt eines langgestreckten Teils angeordnet ist, und ein zweites Ventilmittel (19) an einer intermediären Position in einer Seitenöffnung (18) der Kammer angeordnet ist.

5. Vorrichtung nach Anspruch 3 oder 4, worin die Kanüle (2) mit einem Ende der Kammer (1) kommuniziert und das Entlüftungsmittel (5) am oder in Nachbarschaft des entgegengesetzten Endes der Kammer angeordnet ist, so daß bei Verwendung das Entlüftungsmittel (5) so weit wie möglich vom Körper entfernt angeordnet ist, und so daß bei Verwendung das Entlüftungsmittel Luft aus dem obersten Teil der Kammer entläßt.

6. Vorrichtung nach einem der vorhergehenden Ansprüche, worin die äußere Oberfläche der Membran hinsichlich der Kammer im wesentlichen bündig mit der umgebenden äußeren Oberfläche der Einrichtung liegt.

7. Vorrichtung nach einem der vorhergehenden Ansprüche, worin das Leitungsteil einen Adapter (8) darstellt, der Mittel (10) zur Befestigung des Leitungsteils an der Einrichtung im offenen Zustand des Ventilmittels beinhaltet.

8. Vorrichtung nach einem der vorhergehenden Ansprüche, worin die Membran aus einem unvernetzten Gummimaterial oder aus Silikongummi hergestellt ist.

Drawing